The present invention concerns the use of shielding of critical signal lines within circuitry in order to protect against reverse engineering.
A considerable amount of engineering time and expense is required to develop sophisticated devices. Rather than make this investment, some elect to limit costs by reverse-engineering existing designs. It is desirable for those making a significant investment in an original design to make it more difficult to reverse-engineer a product.
Various techniques exist by which logic within a circuit may be disguised so that it is difficult to visually detect logic design. However, the ability to reverse-engineering designs using electrical monitoring and modification of circuits has been aided by such advances in technology as electron beam probing and ion milling.